1. Field of the Invention
This invention pertains to a folding door which is opened and closed by folding and unfolding a plurality of door sections. More specifically, the invention is directed to an improved swivel roller assembly for use in such a folding door.
2. Description of the Prior Art
In a folding door of the type under consideration, two or more door sections or panels are usually hinged together. One of the stiles of the door is further hinged to one of the side jambs so that the several door sections may be disposed in coplanar relationship to each other in the plane of the doorframe when the door is closed. In opening or closing the door, the other, opening side stile is required to move in the doorframe plane as guided by the header and sill tracks of the doorframe.
Usually, the opening side stile of the folding door is equipped with roller assemblies at its top and bottom ends for rolling engagement with the header and sill tracks. The roller assembly at the top of the stile can be in the form of a simple roller mounted on an upstanding pivot pin. The roller assembly at the bottom, however, must be of sturdier build as it is required to bear the vertical load of the folding door; nevertheless, the bottom roller assembly must be capable of rolling smoothly along the sill track while permitting easy swivelling motion of the opening side stile.
It has been known to incorporate a ball bearing or the like in such a bottom roller assembly. This known roller assembly is objectionable because of its expensiveness, among other reasons.